1. Field of Invention
A pair of integrated ramps attach to the rear of a trailer or utility cargo bed, the ramps swinging on a horizontal plane from a stored position and then being rotated to form a pair or flat ramps surfaces which slide along the rear end of a trailer on a secure end railing to adjust the width of the ramps for the purpose of off loading cargo carried upon the cargo surface of the trailer, the ramps forming a stable angled surface between the cargo bed and the ground.
2. Description of Prior Art
A preliminary review of prior art patents was conducted by the applicant which reveal prior art patents in a similar field or having similar use. However, the prior art inventions do not disclose the same or similar elements as the present trailer ramps, nor do they present the material components in a manner contemplated or anticipated in the prior art.
Several ramps are intended for use for pickup tailgates, but could be readily adapted to a trailer, since a trailer end and a pickup tailgate are relatively similar. These type prior art patents either attach to the tailgate or emanate from the tailgate. In U.S. Pat. No. 7,549,692 to Washington, a pair of telescoping ramps extend from within a tailgate and telescopically side out to form a ramp with a trough which may be pivotally lowered to the ground forming the ramp between the pickup bed and the ground. A near identical set of ramps is disclosed in U.S. Pat. No. 5,536,058 to Otis. Sliding ramps stored within the pickup bed side panels have an upper lip which slip into a tailgate groove providing the ramps at adjustable widths in U.S. Pat. No. 7,344,184 to Salvador. In U.S. Pat. No. 5,540,474 to Holland, a set of folding panel ramps which attach to the tailgate by clamping means, attach to the tailgate and then the panels are folded from one another forming the extension ramp being two axial panels with a central hinge.
A bracket made of a heavy angle iron strip, a pair of spaced bolster embracing plates and having an end welded to the inside of the angle iron and three pivot ears welded to the outside surface of one flange of the angle iron attach to the bed of a vehicle and provide a location for the placement of a ramp which may be pivotally extended to the ground forming an angled surface between the ground and the loading bed in U.S. Pat. No. 2,559,712 to Dobbs.
Truck beds also provide for several varieties of interactive ramps. In U.S. Pat. No. 5,035,565 to White, a pair of ramps are attached to the rear end the bed of the vehicle and have lowered extension which are inserted within slotted members at the rear end to provide the ramps at an angle between the ground and the loading surface. In U.S. Pat. No. 5,678,984 to Peterson, a detachable folding panel ramp attaches to the back of a flatbed tractor trailer with hydraulic piston to raise and lower the ramp and also to fold the ramp into upon itself.
A combination tailgate and ramp assembly is disclosed in U.S. Pat. No. 5,211,437 to Gerulf, which provides a pair of ramps which, when fastened together with fastener brackets form a conventional tailgate, hinged and rotatable about a transverse side rails. These ramps are lowered like a tailgate with outside fastening brackets lowered from below the outside edges of the ramps and the ramps are then separated outward on the pivotal swing pins attaching the outer top edges to a slide rail. Each ramp is then rotated outward while swing pin hinges slide along the slide bar until the swing pin hinges are as far to the respective outside edges of the rail as possible. The outer edges of the flat positioned ramps are then locked within the fastener brackets below and on the outside of each of the ramps, each ramp held along the slide rail by slidable cam spacers to support the free end of the ramp against the slide rail. The swing pins are rotatable along two transverse axis.
Hinge-mounted trailer tailgate ramps are also disclosed in U.S. Pat. No. 3,972,428 to Love, Jr., which involve a pair of tailgate members that attach to the rear end of a trailer by an L-shaped hinge structure. A short end of the hinge structure is attached to a side frame member by a pair of bearings at the rear of the trailer frame, with a long portion being inserted through an upper end of each ramp, with spaced stops holding the upper end of the ramp upon the long end of the hinge structure to prevent sliding of the ramp upon the hinge structure. The ramps are folded out from a tailgate position, rotated and lowered into a ramp position with the exposed terminal end of the long portion of the hinge structure captured within respective hook members at the rear of the trailer. The upper end of the ramp is also supported by fixed support angles welded onto the rear end of the trailer.